Method and apparatus for drawing sheet glass



Dec; so, 1

A J. c. HENDERSON METHOD AND APPARATUS FOR DRAWING SHEETCLASS Filed Nov. lOl 1923 3 Sheets-Sheet l Dea/30, 1924. 1,521,294

J. C. HENDERSON METHOD AND APPARATUS FOR DRAWING SHEET GLASS Fled'Nov. 1o, 1925 s sheets-sheet :5

lll,

1:11 I awww l Patented Dec. 3o, 1924.

UNITED' SZTATVES PATENT' OFFICE."

JOHN C. HENDERSON,. OF NEW YORK, N. Y., ASSIGNOR TO THE LIBBEY-OWENS SHEET GLASS `COMPANY, OFl TOLEDO, OHIO, A CORPORATION OF OHIO.

METHOD AND APPARATUS FOR DRAWING SHEFJI' GLASS.

Application led November 10, 1923. l Serial No. 673,882.

, This invention relates to the art of draw-i ing a continuous sheet of glass, and more particularly tov an improved method and apparatus for bending the plastic glass sheet from one plane to another without injuring the surfaces thereof.

In certain well-known systems forv producing sheet glass, for example the Colburn process ,as set forth in the Colburn Patent, 1,248,809, granted December 4, 1917, the glass sheet is drawn upwardly from a pool of molten glass and then while partially set but still somewhat plastic, is bent through approximately 90? intothe horizontal plane w ere it is carried away through suitable 'drawing and flattening mechanlsm into a I leer. While being bent from thefvertical to the horizontal plane, the sheet is supported' upon someform of bendingmember', usually a highly polished metal roller.- It'is essen.

tial that the cylindrical sheetsupporting surface of this roller beabsolutely smooth,

clean, and maintained at just the proper tem erature, else the delicatey fire-polished sur ace of the plastic sheet will be injured while passing over the roller.

b5 In order to'avoidthe ditliculties incident to the use of such a bending member, the present system has been devised. 'According to the present invention, the plastic sheet, after becoming' partially set, is gripped ad- 40 jacent its edges, and supported by, suitable gripping members which move'with the sheet during its bending period. -Preferably `the sheet edge is gripped between a pair of suitablyguided -and driven endless chains.

These chain loops are so mounted lthat the sheet-gripping runs of the two opposite chains diverge from one another 'as they move with the sheet so that a constantly increasing lateral tension is applied to the glass sheet 'throughout the bending operation. This lateral tension Will prevent sagging of the unsupported main central portion of the sheet, which is carried from the vertical into the horizontal lane without contacting with any solid odie's which might otherwise injure the delicate fire-polished surface of the sheet. v

The objects and advantages ofthis i11- vention will be more :clearl understood from the following detailed escription of an approved form of the apparatus embodying the principles of this invention. In the accompanying drawings:A ,Fig 1 is a vertical longitudinal section through the apparatus, taken substantially on the line 1-1 of Fig. 2. Fig. 2 is a plan view ofthe apparatus, the lower ortion of thel fi urebeing in seo# tion su stantially on the ine 2?--2 :of Fig. 1. Fig. 3 is a transverse vertical Sectlon,

taken` substantially on the line 3"'-3 of Filg. 1.

ig. 4 is a transverse vertical section of one side of the apparatus, taken substantially on the line 4-4 of' Fig. 1.

Fig. 5 is a view, on an enlarged scale, of i a -:fragment of one pair 'of sheet-edge gri ping chains, and a portion'of one 'of t e driving sprockets. f-

Fig. 6 is a transverse vertical section, taken Substantially on the line 6-6 of Fig. 5.

he glass sheet 1 is tirst drawn upwardly from the poolof Inoltenglass 2 in receptacle 3. It is to be understood that the forni of re-A ceptacle 3 here shown is merely illustrative, and that any other approved configuration or proportions could be given' to this receptacle,

'fand that usually means for heating the same will be provided to maintainthe molten glass 2 at the proper working temperature.

Also any approved.- means` either within the molten .glass o'r above the same, `1nay be used to maintain sheet 1 to a fixed width at its source. f*

After sheet 1 has been conveyed from the vertical to the horizontal plane, as hereinafter described, the sheet is carried away through' suitable drawing and' fiattening mechanism,- indicated generally at 4, intothe annealing leer. All ot' tlns may be as shown in systems now in usc and need not be further described here.

Adjacent each side of the machine is mounted a suitable drawing and supporting -n'iechanism for gripping and carrying the y tical into the horizontal plano. These mech- Cil anisms are substantially identical with one another, except that portions thereof are reversed to fit the right and left hand portions of the sheet, Aand a description ol' one set ofmecllanism will sutlice for both. A u

endless gripping and supporting chain 5 is carried by a drlving sprocket 6 within one endV of the chain loop and an idler sprocketl 7 within the -opposite end of the loop.l Chain 5 may be .of the usual sprocket type having teeth 60 on its inner face for engag lng the teeth of the sprocket wheels, and having a somewhat uneven upper face (il4 for insuring a positive grip upon the plastic lass sheet l, Driving sprocket 6 is so positioned that the forward upwardly moving arc-of the chain loop will be tangent to the vertical run of glass sheet l, while the upper horizontal run of the chain loop will lie substantially in the same horizontal plane.

as the sheet-carrying surface of drawing and flattening mechanism 4. endless chain S is carried on suitable sprockets 9 and l0, so positioned that the lower run of chain 8 will travelv over a'nd parallel with that portion of the sheet-carrying run of chain 5 extending from the point of contact of sheet l therewith a't the top ot its vertical run to a point midway along the horizontal travel of sheet l. The tour chain-carrying sprockets 6, 7, 9 and l0, allflie in substantially the same vertical plane .and are carried by the same supporting frame member l1. The shaft 12 of sprocket 6 is mounted in a fixed bearing 13 in this frame.

Shaft 14 of driving sprocket 9 for chainy S, is mounted in a movable bearing 15. rlhis hearinglnay be adpisted 1n the frame ll by means of set-screws 1G to insure the proper spacing between the sheet-engaging runs or chains 5 and 8. 'lhe idler sprocket at the opposite end ot chain loop 5 isicarried by a shaft 17 in bearing lb, slidablyy adjustable in one end ot' trame' ll, by means of setscrew 19. The chain loop `is tightened by suitably adjusting the screw 19.' ln the same manner the upper chain loop 8 is kept tight by adjusting the bearing by means ot' screw 21.

A horizontal drive shaft is mounted iu hearings 23 at the lower edge of frame 111 und shaft 22 is provided willi worms 24 and 25 which drive worm wheels 26' and 27' keyed to the outer endsof shafts 12 and 14 respectively.

A worm 2S at one end .of shaft 22 meshes with and is driven by a worm 29 on vertical shaft 30, which in turn is driven through suitable worm gearing 31'from a horizontal drive Shaft SZeXtending in through oneside of the machine. The supporting frame 11 is mounted on pivot 33 o a fixed supporting bracket Biat the side of the ma- A second' similar.

',tio'n of tl'ie arrow, Fig. l. ln this way a conchine. It will be noted that pivot 33 is coa-Xial with vertical drive shaft 30 so that the driving mechanism, above described, for the two driving sprockets will not be affected by any adjustment ot' supporting frame ll about its pivot 3?.

The vertical supporting member 35, at the" opposite end ot' traine ll, is mounted in th'e. arc'uate groom 3G iu lixed supporting 6 75 bracket lThe arruate slot or groove 3 concentric with pivot member An adjusting screw 23S, extending in through the side of the machine, engages the supporting finemh'er 35, 'and by suitably manipulating this serein the support 35 may he moved along the; arcuate slot llt, whereby the angle which the vert-ical plane of the frame ll and lthe gripping chains 5 and S makes with the side ot' the machine or with th'e centerline of glass sheet l may be varied as desired. The frames ll will ordinarily be so ad-l justed that the two sets of edge-gripping chains diverge from one another as they more forrward with the sheet in the direcstant lateral stretching tension will be ap- 'l plied to th glass sheet during the entire bend-ing operation and during the irst part ,ot its horizontal run. This tension will overcome the tendency for the unsupporte central portion ot thil sheetto sag and will at the saine time draw out wrinkles or .other surface variations which may; have existed in ithe vertical run of the sheet. At 39 is shown means whereby a blast of cold air, or other cooling iiuid, may be blown against the l'oweridle run of chain 5 to cool the same prior to its engagement with the glass sheet.. lt is to he understood that any other fornrot' cooling means might be' used with either or both chain loops to keep them at the proper temperature.

It will be noted that the upper sheet-edge carrying run of chain 5 is slidably sup-A ported upon a horizontal trackway 40, formed 'as un exlensioirof the frame 11. This will prevent sagging oi the upper run ot this chain and insune a flat horizontal travel for the glass sheet. 'lhe upper chain loop 8 is supported in its lower sheet-engag ing run hy the edge portion of the'glass sheet, aud the sprockets 9 and l0 will be so adjusted that the two chain loops will engage the sheet edge between them with suflicient pressure to positively grip the vplastic sheet as indicated in Figs. 5 and 6. This will insure an effective hold upon the sheet edges during the lateral stretching opera tion as abovedescribed.

lt will be noted that with this apparatus the main central portion of the glass sheet .remains entirely untouched throughout its vertical run and until after the bending operation 'has been completed. Before the sheet comes into contact with any Solid Sup porting members in the horizontal lane, it. has becomeiset so that it is less l ia le to injury on its lower {ire-polished surface.

Claims:

1. That improvement in the art of drawing sheet glass, which consists in bending the sheet from one plane to another while unsupported e. .ept at its edges, by gripping the edge-portions of the sheet between memlll bers which move with the sheet throughout the bending operation.

2. That improvement inthe art of drawing sheet glass, which consists -in bending l the sheet from one plane to another while unsupported except at its edges, by gripping the edge-portions of the sheet between members which move with the sheet throughout the bending operation, and simultaneously forcing these gripping members to move along diverging paths so that lateral tension isapplied to the glass sheet.

3. That improvement in the art of drawing a continuous sheet of glass from a molten source, consisting in first drawing the sheet upwardly, and then bending the 'sheet into a substantially horizontal plane,

while unsupported except adjacent its edges, the edge portions of the sheet being gripped while in its vertical run between means which move with the sheet throughout the bending operation.

4. That improvement in the art of drawmg a continuous sheet of glass from amolten' source, consisting in first drawing the sheet upwardly, and then bending'the sheet into a substantially horizontal plane,

while unsupported except adjacent its edges, the edge portions of the sheet being gripped while in its vertical run between ineans which move with the sheet throughout the bending operation,- the gripping means at Aopposite edges of the sheet moving away from one :mother during the bending operation to apply lateral tension to thc glass sheet.

5. In a sheet glass drawing apparatus, means fo'r bending the sheet from one plane to another, comprising la continuous series of gripping elements engaging and moving with the sheet edges and supporting the same throughout the bending operation.

la a sheet glass drawing apparatus,

means for bending the sheet from one plane to another, comprising a continuous series of gripping elements en aging and moving ing operation,

. ln a sheet glass drawing apparatus,

means for bending the sheet from the ver? tical to the horizontal plane, comprising pair of cooperating chainloops at each e g e of the sheet, the sheet'edge being gripped means for bending the sheet fromthe ver-j tical to the horizontal plane, comprisin a pair of cooperating chairtloops at each edge of the' sheet, the sheet edge being gripped and carried between adjacent runs of the loops, fruidin means for the chain-loops whereby their sheet-engaging runs are '55 with the sheet edges an drawing the same forwardly and outwardly during the bendcaused to diverge and stretch thesheet bent, and means laterally while it is bein divergence of the for adjusting the angle o guidin means.

10. n a sheet glass drawing apparatus,

means forbending the sheet -from the vertical to the horizontal plane, comprising a pair of cooperating chain-loops at carried between adjacent runs of t e loops, a drivlng sprocket carrying one end of each loop, 'and anidler sprocket carrying the other end, a supporting frame in whieh all of thesprockets are mounted, and means for .varying the inclination of this frame with res ectto the center-line of the glass sheet.

igned at Harrison. in the county of Hudson, and State of New'Jersey, this 5th day of November, 1923.

JOHN C. HENDERSON.

each edge of the sheet, the sheet edge being gripped and 

